Asbestos Clutch Disc

The asbestos clutch disc, also known as a clutch plate or clutch facing, is a critical friction component in manual transmission vehicles. It sits between the flywheel and the pressure plate, engaging and disengaging the engine from the drivetrain each time the driver operates the clutch pedal. Asbestos was the material of choice for clutch facings from the 1930s through the early 2000s due to its outstanding combination of heat resistance, friction coefficient stability, and wear durability under the intense heat and pressure of the clutch engagement cycle.

Major manufacturers such as Borg & Beck, Ferodo, Sachs, and Valeo produced asbestos clutch facings for original equipment and aftermarket applications across the global automotive market. The asbestos content, typically chrysotile, ranged from 30 to 60 percent by weight, bonded with resins and reinforced with metal wire or woven backing.

Exposure to asbestos from clutch discs occurs primarily in automotive workshops during clutch replacement. When a worn clutch disc is removed from the bell housing, accumulated dust containing asbestos fibres is released into the workspace. The bell housing acts as an enclosed chamber that traps wear debris over thousands of clutch engagements, similar to how a brake drum accumulates dust. Mechanics who performed clutch replacements as a routine part of their work experienced repeated exposure, particularly before awareness of asbestos hazards became widespread in the automotive trade.

Borg & Beck, one of the most recognised clutch manufacturers in the world, supplied asbestos-faced discs to nearly every major vehicle maker. Their products were installed in millions of vehicles across Europe, North America, Asia, and the Southern Hemisphere. Workshop exposure was not limited to mechanics; apprentices, parts counter workers, and even drivers who performed their own maintenance were at risk.

When new, the asbestos facing is tightly bound in resin and classified as non-friable. As the clutch wears through normal operation, the facing material becomes progressively more friable, shedding fibres into the bell housing. The risk level is rated at 3 because exposure events, while potentially intense, are less frequent than brake work, occurring only at clutch replacement intervals typically measured in tens of thousands of kilometres.